| Message ID | 20170321134203.26325-5-andrew.smirnov@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
Am Dienstag, den 21.03.2017, 06:42 -0700 schrieb Andrey Smirnov: > Save a bit of time and avoid going through link speed change procedure > in configuration where link max speed is limited to Gen1 in DT. > > Cc: yurovsky@gmail.com > Cc: Lucas Stach <l.stach@pengutronix.de> > Cc: Bjorn Helgaas <bhelgaas@google.com> > Cc: Fabio Estevam <fabio.estevam@nxp.com> > Cc: Dong Aisheng <dongas86@gmail.com> > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Reviewed-by: Lucas Stach <l.stach@pengutronix.de> > --- > drivers/pci/dwc/pci-imx6.c | 52 +++++++++++++++++++++++----------------------- > 1 file changed, 26 insertions(+), 26 deletions(-) > > diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c > index c731e41..9407c03 100644 > --- a/drivers/pci/dwc/pci-imx6.c > +++ b/drivers/pci/dwc/pci-imx6.c > @@ -533,40 +533,40 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie) > tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK; > tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2; > dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp); > - } else { > - dev_info(dev, "Link: Gen2 disabled\n"); > - } > - > - /* > - * Start Directed Speed Change so the best possible speed both link > - * partners support can be negotiated. > - */ > - tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL); > - tmp |= PORT_LOGIC_SPEED_CHANGE; > - dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp); > > - if (imx6_pcie->variant != IMX7D) { > /* > - * On i.MX7, DIRECT_SPEED_CHANGE behaves differently > - * from i.MX6 family when no link speed transition > - * occurs and we go Gen1 -> yep, Gen1. The difference > - * is that, in such case, it will not be cleared by HW > - * which will cause the following code to report false > - * failure. > + * Start Directed Speed Change so the best possible > + * speed both link partners support can be negotiated. > */ > + tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL); > + tmp |= PORT_LOGIC_SPEED_CHANGE; > + dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp); > + > + if (imx6_pcie->variant != IMX7D) { > + /* > + * On i.MX7, DIRECT_SPEED_CHANGE behaves differently > + * from i.MX6 family when no link speed transition > + * occurs and we go Gen1 -> yep, Gen1. The difference > + * is that, in such case, it will not be cleared by HW > + * which will cause the following code to report false > + * failure. > + */ > + > + ret = imx6_pcie_wait_for_speed_change(imx6_pcie); > + if (ret) { > + dev_err(dev, "Failed to bring link up!\n"); > + goto err_reset_phy; > + } > + } > > - ret = imx6_pcie_wait_for_speed_change(imx6_pcie); > + /* Make sure link training is finished as well! */ > + ret = imx6_pcie_wait_for_link(imx6_pcie); > if (ret) { > dev_err(dev, "Failed to bring link up!\n"); > goto err_reset_phy; > } > - } > - > - /* Make sure link training is finished as well! */ > - ret = imx6_pcie_wait_for_link(imx6_pcie); > - if (ret) { > - dev_err(dev, "Failed to bring link up!\n"); > - goto err_reset_phy; > + } else { > + dev_info(dev, "Link: Gen2 disabled\n"); > } > > tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCSR);
diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c index c731e41..9407c03 100644 --- a/drivers/pci/dwc/pci-imx6.c +++ b/drivers/pci/dwc/pci-imx6.c @@ -533,40 +533,40 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie) tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK; tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2; dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp); - } else { - dev_info(dev, "Link: Gen2 disabled\n"); - } - - /* - * Start Directed Speed Change so the best possible speed both link - * partners support can be negotiated. - */ - tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL); - tmp |= PORT_LOGIC_SPEED_CHANGE; - dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp); - if (imx6_pcie->variant != IMX7D) { /* - * On i.MX7, DIRECT_SPEED_CHANGE behaves differently - * from i.MX6 family when no link speed transition - * occurs and we go Gen1 -> yep, Gen1. The difference - * is that, in such case, it will not be cleared by HW - * which will cause the following code to report false - * failure. + * Start Directed Speed Change so the best possible + * speed both link partners support can be negotiated. */ + tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL); + tmp |= PORT_LOGIC_SPEED_CHANGE; + dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp); + + if (imx6_pcie->variant != IMX7D) { + /* + * On i.MX7, DIRECT_SPEED_CHANGE behaves differently + * from i.MX6 family when no link speed transition + * occurs and we go Gen1 -> yep, Gen1. The difference + * is that, in such case, it will not be cleared by HW + * which will cause the following code to report false + * failure. + */ + + ret = imx6_pcie_wait_for_speed_change(imx6_pcie); + if (ret) { + dev_err(dev, "Failed to bring link up!\n"); + goto err_reset_phy; + } + } - ret = imx6_pcie_wait_for_speed_change(imx6_pcie); + /* Make sure link training is finished as well! */ + ret = imx6_pcie_wait_for_link(imx6_pcie); if (ret) { dev_err(dev, "Failed to bring link up!\n"); goto err_reset_phy; } - } - - /* Make sure link training is finished as well! */ - ret = imx6_pcie_wait_for_link(imx6_pcie); - if (ret) { - dev_err(dev, "Failed to bring link up!\n"); - goto err_reset_phy; + } else { + dev_info(dev, "Link: Gen2 disabled\n"); } tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCSR);
Save a bit of time and avoid going through link speed change procedure in configuration where link max speed is limited to Gen1 in DT. Cc: yurovsky@gmail.com Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Fabio Estevam <fabio.estevam@nxp.com> Cc: Dong Aisheng <dongas86@gmail.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> --- drivers/pci/dwc/pci-imx6.c | 52 +++++++++++++++++++++++----------------------- 1 file changed, 26 insertions(+), 26 deletions(-)